Blog exposure - before or after beta?

We're getting close to launching a new product, and I'm trying to decide the right timing for press. We plan to run an invite only beta for a week or two, followed by a larger beta group before opening up fully.

The web app will be subscription-based following the beta tests. I'm interested in hearing others opinion on the timing for submitting to blogs, influencers, etc. If we decide to "buzz" the product prior to full launch, we'll only be taking beta sign-ups. We could offer the larger blogs with a limited number of sign-ups, etc. The alternative is to wait until we're fully launched so visitors from the blog can immediately sign-up and start using the product (30-day trial).

We want to take full advantage of any exposure we can get, so I want to make sure I get the timing right. Would you start the press while you're in beta, or wait? Why?

To clarify : I'm speaking of press on the popular industry blogs. We're fairly sure we'll get a good amount of coverage, I just want to time the influx of traffic correctly - signup for beta vs. we're live.

It depends how widely interesting your product is and how good your marketing team is.

If you have a product that is really gonna galvanize a core audience around it, then you might be able to get some good press prior to launch.

However, that's contingent on you having people who know how to put out a steady stream of meaningful, interesting content that will reach the right people. Just writing a blog doesn't cut it. You need dedication and effort to get buzz going.

If you don't have those things now, then wait until you launch the product and can get people interested by letting them see, touch, hear, smell or taste what it is you've got for them. Then maybe they'll want to read what you have to say.

I agree with Gabriel's last point.

Beyond a "tell me when it's ready" signup, you should make your main promotional push when you have something that people can log into and play with. If you don't have a product, they'll get excited about the idea and then forget all about your product by the time it's ready for them to actually use.

I agree with Paul McMillan (but then I have yet to disagree with him), that you should wait until you are ready for it to be used.

It is a matter of setting expectations.

If you announce and aren't ready, people may think it is vapor-ware, that it will never truly be ready.

When you start to talk about it in public forums, ensure that you are open about what is currently available, if it is not feature complete, don't stress the parts that aren't done, as you will set an expectation that you aren't ready to meet.